Make sure to keep them sealed in something a bag or box.
Keep them away from windows as well. I've also found that adding silica packets into that box works wonders.
There are dessicant packs that are specifically designed for use with food. They can be found in many packaged foods.
Here's an example on Amazon: https://www.amazon.com/gp/product/B004FC5VT4?sa-no-redirect=1&pldnSite=1
$6 Canadian will get you enough . https://www.amazon.com/Packs-1GrCotton-20pk-Silica-Desiccants-Packets/dp/B004FC5VT4
I think your looking for desiccant packets here's one on amazon .
Something like this haus http://www.amazon.com/Packs-1GrCotton-20pk-Silica-Desiccants-Packets/dp/B004FC5VT4